Supporting procedural constructs in existing SQL compilers

The draft ofthe SQL/PSM standard denes a procedural extension to the existing SQL2 language. An essential part of this extension is the support of procedural constructs such as BEGIN/END blocks, local variables, assignment statements, conditionalstatements, and variousformsof loops. Such an extension introduces new challenges to existing SQL compilers. Most SQL compilers exiting in the marketplace today were built based on the declarativeness of SQL. The question is how these procedural extensions can be best implemented in a relational DBMS without losing the power of existing query optimizationmechanisms. So far, most implementationsof the SQL procedural extensions rely on the use of a separate interpreter to handle the procedural statements so that the existing SQL compiler can be left untouched. Although this approach is quite easy to implement (as it followsthe paradigmcurrently used between SQL and host languages), it does not provide the best possible performance. In this pape...

• Type: Conference
• Year: 1996
• Where: CASCON
• Authors: Gene Fuh, Jyh-Herng Chow, Nelson Mendonça Mattos, Brian T. Tran
• Keywords: CASCON 1996, CASCON 2007, Procedural Constructs, Procedural Extensions, Sql Compiler